CMMMech
CMMMech > Mineral group > Olivine group

Olivine group mineral group

Olivine denotes a mineral group, identified as GROUP in the CNMNC-hosted Compendium of IMA-approved Mineral Nomenclature. The forsterite-fayalite solid-solution series lies within this group; a magnesium-rich experimental olivine is not necessarily the chemically pure forsterite endmember. This record keeps group scope distinct from the existing forsterite species record, elemental constituents and bulk ultramafic resources. No group-wide criticality or uniform microbial response is inferred. The enstatite companion record uses a different feed arm of the same Klug study.

Microbial & Biochemical Mechanisms (1)

Bioleaching of magnesium-rich San Carlos olivine with secondary oxalate formation

bioleaching Microbial

Associated Organisms: Gluconobacter oxydans (NCBITaxon:442)

The authors' selected olivine-only powder released Mg and Ni in both cell-containing and cell-free Gluconobacter oxydans biolixiviant experiments. Direct cultures had higher final filtrate Mg than the cell-free arm. Residues contained author-assigned Mg-oxalate and amorphous silica; this is conditional transformation of the tested magnesium-rich olivine, not proof of a response shared by every group member.

Experimental Context & Analytical Limits:
The selected San Carlos powder was reported as 100% olivine by XRD after removal of pyroxene grains. That phase-purity statement is distinct from pure-endmember chemistry: Table S1 assumes 90.68% Fo from earlier commercial material. The separate 69/31 olivine/enstatite experiment is not pooled with this arm. The strain was Gluconobacter oxydans B58 delta-pstS, P112:mgdh, propagated from one colony; triplicate flasks per arm and sampling day were technical replicates from that shared culture. YPM growth and glucose-based biolixiviant production each lasted two days at 30 degrees C and 200 rpm. Prepared cell-containing cultures and centrifuged, 0.2-micrometre-filtered biolixiviant were tested separately. Each 100-mL flask contained 10 mL liquid and 0.5 g powder (5% pulp), incubated statically at 30 degrees C for 0, 5, 10 or 15 days. The Methods temperature takes precedence over the Introduction's room-temperature shorthand. Powders had typical particle size 40 micrometres after 20 minutes of tungsten-carbide milling; visibly carbonate-coated/altered grains were removed and a 60-minute deionized-water ultrasonic wash preceded milling. Powder sterilization was 135 degrees C for three minutes. Controls contained 20% glucose and mineral without cells or biolixiviant, with no acid or pH matching. Species taxon 442 does not identify the engineered genotype.
Curated Evidence Points:
ICP-MS data row 6 reports day-15 Mg means of about 9565 ppm with cells (O6), 7203 ppm with cell-free biolixiviant (Y6), and 242 ppm in the glucose-only olivine control (E6). XRD minerals rows 4, 10 and 14 assign respectively 32, 20 and 0 wt% Mg-oxalate in residual solids, with associated amorphous-silica fractions. These phase fractions are not isolated-product yields. The workbook's ppm-to-mg/L convention is retained only in prose, without conversion to mg/kg.
Figure S3 compares direct and cell-free olivine XRD series and preserves Mg-oxalate formation in the cell-free day-15 residue. Figure S1 presents a background-subtracted Raman spectrum assigned to glushinskite. These are the authors' phase assignments; no new separate generic magnesium-oxalate species is created here. Table S1 makes the imported-composition assumption explicit.
Figure 6a and the Discussion allocate about 64% of initial Mg to solution and 11% to Mg-oxalate at day 15, together accounting for the reported roughly 75% liberated from starting olivine. The Abstract instead calls the 11% a proportion of leached Mg; these denominators conflict and are not silently harmonized. The values are mass-balance estimates using assumed starting chemistry, 10 mL liquid and XRD proportions, not a weighed isolated yield or 75% dissolved Mg. Carbon in the oxalate likely derives from glucose; net atmospheric capture and long-term storage are unestablished.
Leachate was centrifuged at 3214 x g for 20 minutes, frozen, thawed, passed through 0.45-micrometre filter plates and diluted 10000-fold in nitric acid for ICP-MS. Reported Mg and Ni were blank-corrected by about 1043 and 3.2 ppm respectively using a 100-fold-dilution comparison. These operationally defined filtrate concentrations are not isolated-product yields or resolved chemical species. Initial treated pH was about 2.4-2.5 but controls were about 8.7; later direct and cell-free pH trajectories also differed. The experiment does not isolate physical contact from evolving acid/metabolite chemistry, demonstrate a particular Fe-oxidation enzyme, or compare this mutant with wild type for mineral leaching. Laboratory results establish no industrial deployment or net atmospheric carbon removal. Oxalic acid was detected in only one mutant biolixiviant replicate; its concentration was not quantified, and proposed Fe oxidation/siderophore effects remain mechanistic interpretations.

Sources & References

  1. ima_compendium: A Compendium of IMA-approved Mineral Nomenclature, Melbourne 2018 compilation, copyright 2019; CNMNC-hosted PDF pages 10 and 16, forsterite-fayalite examples; page 35, Whitney and Evans mineral-abbreviation table, olivine GROUP row and footnote.
    https://cnmnc.units.it/ima_reports/2%20IMA-Nomenclature-e-Booklet-2019-1.pdf (accessed 2026-10-11)
  2. klug_2026: Klug et al. (2026). Bioleaching of olivine and enstatite with formation of Mg-oxalate mediated by engineered Gluconobacter oxydans. Scientific Reports 16:25317. DOI 10.1038/s41598-026-63817-0; Methods, Figures 2-6 and Discussion.
    https://doi.org/10.1038/s41598-026-63817-0 (accessed 2026-10-11)
  3. klug_2026_data: Klug et al. (2026), Supplementary Material 1: leachate pH, ICP-MS data, XRD minerals and Mg, Fe, Ni mass balance calcs worksheets. Same experiment as the main article.
    https://pmc.ncbi.nlm.nih.gov/articles/instance/13473492/bin/41598_2026_63817_MOESM1_ESM.xlsx (accessed 2026-10-11)
  4. klug_2026_si: Klug et al. (2026), Supplementary Material 2: Table S1 and Figures S1-S4; assumed commercial San Carlos composition, Raman assignment, feed mixture and direct versus cell-free XRD.
    https://pmc.ncbi.nlm.nih.gov/articles/instance/13473492/bin/41598_2026_63817_MOESM2_ESM.docx (accessed 2026-10-11)
  5. ncbi_oxydans: NCBI Taxonomy 442 - Gluconobacter oxydans, species rank; XML checked 11 October 2026. This identifier does not resolve the engineered B58 derivative.
    https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=442&mode=Info (accessed 2026-10-11)

Curation History

Timestamp Curator Action Summary
2026-10-11T10:51:48.882231+00:00 codex (GPT-6; codex) CREATE Created olivine group record with bounded San Carlos bioleaching, cell-free comparison and denominator uncertainty.

Record source: data/records/olivine-group.yaml